LAN configuration using Iphone, switch, and 3 clients

Hello,

I'm have set up a LAN for my office which is working well except for providing Internet access for all machines via an Iphone using its personal hotspot capability. I have 3 PC's (desktop, laptop, desktop2) that are connected via a switch (diagram below). They all communicate fine amongst themselves. One PC (desktop) is also connected to the Iphone for internet access. That connection works fine, PC to internet, PC to LAN. The other PC's (laptop, desktop2) can see the Iphone via ping, however, I can't seem to figure out how to get them to route their internet requests through the first PC (desktop) to the Iphone. I have packet forwarding turned on on the Iphone PC (desktop), but I don't know what else is needed. Ubuntu 13.11

Re: LAN configuration using Iphone, switch, and 3 clients

Sorry for the slow reply, was off-line for a couple of days. Couple of reasons for not using WiFi. My laptop's WiFi isn't supported and my phone is one of several phones on a business plan and we can't get WiFi hot spot capability. I was originally hoping to use my desktop as a WiFi hotspot and having the Iphone tethered to it but that didn't work due to the laptop. I've tried configuring the other machines to point at the Iphone as the DNS server but that doesn't work. I'm thinking that the solution may involve setting up the desktop as a router that will handle the DNS and routing services but I'm not sure how to go about it. I am able to move the Iphone to the laptop so I can access the web, but desktop2 is a new box and I upgraded the Iphone to IOS7 before I got it, so I can't get desktop2 and the Iphone to work together. The Iphone refuses to permit the connection even though I tell it to trust the box. The other 2 computers were connected under IOS6 so they were 'grandfathered' in and can still connect. Desktop and desktop2 are running Ubuntu 13.11 and the laptop is 13.04.